Sodium chlorite manufacture

Large-Scale Industrial Production. Large amounts of chlorine dioxide ate used in pulp bleaching and smaller quantities ate used for the manufacture of sodium chlorite. In these appHcations, sodium chlorate is the only commercially available taw material. Chlorine dioxide production from sodium chlorate is achieved by the reduction of the chlorate ion in the presence of strong acid. The reaction consumes acid, so that acid and reducing agents must be constantly added to maintain the reaction. 

The commercial manufacture of sodium chlorite is based almost entirely on the reduction of chlorine dioxide gas in a sodium hydroxide solution containing hydrogen peroxide [7722-84-1] as the reducing agent. The chlorine dioxide is generated from the chemical or electrochemical reduction of sodium chlorate under acidic conditions. 

CMA. 1991. Chemical Manufacturers Association. Initial submission Letter submitting preliminary information from an acute inhalation study in rats on sodium chlorite with attachment. CMA/88-920000094. 

CMA. 1996. Chemical Manufacturers Association. Sodium chlorite drinking water rat two-generation reproductive toxicity study. Quintiles Report Ref CMA/17/96. 

There are several methods of manufacturing is on a commercial scale, for instance the calcination of oxalic add blended with potassium chloride, treatment of sodium chlorite with chlorine, or of sodium chlorate with sulphur dioxide in the presence of concentrated sulphuric add. Chlorine dioxide is utilized as a strong bleaching agent for cellulose, paper, flour, oils and such like, as well as a solvent for removing lignin from wood pulp. 

Sodium chlorite (NaC102) is manufactured from chlorine dioxide, sodium hydroxide, and calcium hydroxide. 

The manufacture of sodium chlorite starts from chlorine dioxide C102. It can easily be prepared in a laboratory by heating a mixture of powdered potassium chlorate and oxalic acid to 70 °C. The gas escaping will contain carbon dioxide and chlorine dioxide. 

Chlorine dioxide is manufactured on site as the gas cannot be stored in compressed form it is explosive under pressure. Several methods are used to generate chlorine dioxide. The most common method involves the reaction of chlorine gas with sodium chlorite to form chlorine dioxide and sodium chloride ... 

Theoretically, 1 pound of chlorine gas is required for each 2.6 pounds of sodium chlorite. In practice, however, an excess of chlorine is used to lower the pH to about 3.5 and drive the reaction to completion. In reality, the reaction never goes to completion, and there is always free chlorine in equilibrium with the chlorine dioxide. For this reason, membrane manufacturers discourage the use of chlorine dioxide for disinfecting RO systems.11... 

In the bleaching of fibers for the manufacture of paper and textiles, sodium chlorite (NaC102) and/or chlorine dioxide (C102) is often used because of the ability to achieve excellent whiteness without as much fiber... 

Sodium chlorite is manufactured on a ton scale for use as a bleaching agent. In alkaline solution the ion is stable to prolonged boiling and up to a year at 25°C in the absence of light. In acid solutions, however, the decomposition is rapid and is catalyzed by Cl ... 

Sodium chlorite is an active bleaching agent, used in the manufacture of textile fabrics. 

When large quantities are required, it is manufactured from sodium chlorate, for smaller quantities from sodium chlorite. 

Sodium chlorite is utilized primarily for the small scale manufacture of chlorine dioxide. 

Chlorine dioxide is generally manufactured against demand and is applied as a solution (see Table 14.8). It cannot be transported and stored because it is unstable and liable to decompose with explosive force. It is generated in situ from sodium chlorite and chlorine according to the equation ... 

Sodium chlorite is marketed in two forms, as asolid containing approximately 80% sodium chlorite and as an aqueous solution. Sodium chlorite is manufactured by reducing sodium chlorate, chemically or electrochemically, in the presence of hydrochloric acid to produce chlorine dioxide. Chlorine dioxide is then reacted with hydrogen peroxide in aqueous sodium hydroxide to yield a solution containing 30-50% sodium chlorite, which is subsequently dried to a solid or further diluted to get an aqueous solution. 

It is important to follow equipment manufacturer s instructions to generate chlorine dioxide efficiently. Adjustments to chlorine and sodium chlorite feed may be necessary to optimize production and minimize forming unwanted by-products (chlorate, chlorite, or excess chlorine). The high-yield production of chlorine dioxide depends on the relationship of chlorine to sodium chlorite, pH, and other factors. Precise and accurate control of all variables is necessary to produce the highest-purity product and to minimize undesirable byproducts. 

The paste used to manufacture stonewares tiles generally consists of a mixture of plastic clays, kaolin, feldspathic sand, sodium or potassium feldspar and small quantities of talc, dolomite and/or chlorite. The overall chemical composition of the... 

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